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What’s the Speed of Sperm?

As in, how fast do sperm cells swim, but also, how fast does it, y’know, leave the body?

Thousands of us — per Google — are asking “how fast is sperm,” and yet are any of us actually certain of what we’re even asking? Is it how quickly the sperm reaches the egg? At what velocity does semen depart the penis? How fast is sperm in solving a riddle when presented with one by a troll as it tries to cross a bridge? 

Probably the former two questions, though I beg researchers to please begin tackling the third. Oddly enough, it’s a bit of a challenge nailing down precisely how quickly sperm both “swims” and is ejaculated. That might be because, like so many other aspects of sexual health, it varies from person to person (or species).

Some of our most accurate research pertains to the sperm of not only humans, but primates as well. In one 2007 study from the University of California, San Diego, researchers collected sperm from humans, gorillas, chimps and rhesus monkeys. I simply have to point out this quote from a news release about it: “Researchers had collected sperm samples from the latter two species using artificial vaginas, while the gorillas were trained to give up sperm (with the helping hand of a researcher) in exchange for candy.” Um, sorry? 

Moving on. Their data found that human sperm moves at an average rate of 0.2 meters per hour, or .0001 miles per hour. This refers specifically to the speed of the sperm cells themselves moving, rather than the speed at which the semen was ejaculated. In comparing this to the primates, it appears that there is somewhat of a correlation between promiscuity and sperm speed — gorillas, who are highly monogamous, had the slowest sperm, while ultra-promiscuous chimps and rhesus monkeys had sperm that moved at .7 meters per hour. 

Per a Men’s Health article from 2005, semen is ejaculated at a speed of 28 miles per hour, which is rather fast. Other internet sources claim it can reach 31 miles per hour. Unfortunately, there aren’t a ton of academic studies to point to in order to answer this question, but most know from personal experience that there are a wide variety of ejaculations to be had. If you’ve ejacuated a number of times in a short window, your cum might seem to come out more slowly and in a reduced quantity. If you’ve waited a long time to ejaculate, you will indeed produce a larger quantity of sperm and may also feel as though the release itself was faster or more “powerful.” 

However, a 2015 study further supports a hypothesis of human ejaculation similar to that of the monkeys. According to the study published in Evolutionary Psychological Science, men ejaculate more semen and produce more motile sperm when they’re exposed to imagery of a woman they haven’t seen before. As such, it’s possible that the speed at which sperm swims might even depend upon the specific circumstances under which it’s released. Presumably, the speed at which it leaves the penis could vary, too. 

In other words, it probably all depends on the person and their habits. Now that we’ve established that, can we please start figuring out how quickly a sperm cell can solve a riddle? The troll is waiting!